Manufacture of films for photographic purposes.



J. H. SMITH. MANUFACTURE OF FILMS FOR PHOTOGRAPHIG PURPOSES. APPLICATION FILED JULY 16, 1906.

Patented June 1,1909

. JOHN HENRY SMITH, OF ZURICH, SWITZERLAND.

MANUFACTURE .OF FILMS FOR PHOTOGRAPHIC PURPOSES.

Specification of Letters Patent.

Patented June 1, 1909.

' Original application filed may 15, 1905, Serial No. 260,436. Divided and this application filed July 16, 1 906.

Serial No.

To all whom it may concern:

Be itknown that I, JOHN HENRY SMITH, a subject ofthe King of Great Britain, residing in Zurich, in the Canton of Zurich, Itepublic of Switzerland, (whose post-office address is No. 417 Seestrasse, Zurich, Switzerland,) have invented certain new and useful Improvements in the Manufacture of Films for Photographic Purposes; and Ido hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawln'gs, and to letters of reference marked thereon, which form a part of this s ecification.

The resent application is a ivisio'n of my co-pen mg appi SenalNo. 2604.36. 1

propriate smooth support a gelatin solution and after drying coating upon this again a solution of nitrocellulose. A sensitive photographic emulsion is coated upon the dried intro-cellulose surface and after the emulsion is dried, the triple film is stripped from its support. A second film is prepared in'the same manner omittin however the coating of the sensitive emulsion and this is also stripped from its support. The plain gelatin surfaces of the two componentfilms are then brought into contact and squeegeed together in amoist condition yielding the finished compound film shown in -1 in which a, a, are the layersof gelatin, 1), b, the layers of collodion and c the layer of sen sitive photographic emulsion,

Instead of making two separate films, one only need'to be made and the half 'of the film only coated with the sensitive emulsion,

then the whole film stripped from itssupport, doubled up with'the plain gelatin surface inside andsqueegeed'togethen to form the compound film seen in Fig. 2. Or again cation filed May 15, 1905,-

The subject of the present invention is an the compound film may be formed by either of the above methods but without the intermediate coating of the sensitive emulsion and the emulsion then coatedupon the finished compound film after stripping.

In order that the emulsionshould adhere tenaciously to the nitro-cellulose surface a substratum consisting of a'soflution of gum arabic or other suitable-binding agent may be applied before the emulsion is coated.

Camphor, resins, balsams, oils, parafiins etc. may be addedto the nitrocellulose solutions to increase the pliability or render the inner, gelatin layer more 1mpermeable by the photographic baths etc. or to render the process more economical.

Instead of squeegeeing two component films together one only may be taken and the back or plain gelatin surface coated with a nitrocellulose solution after stripping, either before or after v the sensitive emulsion has been coated (see Fig. 3).

What I claim is 1. The hereindescribed process for manu-- facturing a sensitive photographic film consistmg 1n squeegeeing together into intimate contact two layers. of gelatin which havebeen previously coated with a protecting layer of nitrocellulose solution and coating one of the layers of nitrocellulose solution with a sensitive photographic emulsion.

2. The hereindescribed process for manufacturing a sensitive photographic film consistlng in coating a gelatin layer with a nitrocellulose solution, coating the nitrocellulose solution with a sensitive photographic emulsion, stripping the whole from its support. andcoating the plain gelatin surface with a nitrocellulose solution.

In testimony whereof, I have signed 'my name to this specification in the presence of two subscribing witnesses.

JOHN HENRY SMITH:-

Witnesses A. LIEBERKNEoHT, HERMANN HUBER. 

